Star Once Passed 'Astronomically Close' to Earth
It was less than a light-year away
By John Johnson,  Newser Staff
Posted Feb 18, 2015 3:49 PM CST
File photo: This handout composite image provided by NASA shows the visible and near infrared light spectrum collected from NASA's Hubble Space Telescope over a nine-year period.   (AP Photo/NASA)

(Newser) – Somewhere out there is a trivia question asking for the name of the star closest to our solar system. The answer has long been Proxima Centauri, a mere 4.2 light-years away. But now astronomers say that another star came five times closer about 70,000 years ago, they write at Eureka Alert. The red dwarf known as Scholz's star came within 0.8 light-years of the sun when it passed through something known as the outer Oort Cloud, described as a region at the edge of our solar system filled with comets. Assuming the calculations described in Astrophysical Journal Letters are correct, this is the closest any star has ever come to us, explains NBC News. The distance of 5 trillion miles is considered "astronomically close."

In fact, it came so near that our ancestors could have seen flare-ups lasting minutes or hours if they happened to glance up at the night sky. While a fly-by this close has the potential to create havoc, it appears that Scholz's star did no such thing. "There are trillions of comets in the Oort Cloud and likely some of them were perturbed by this object," a lead researcher from the University of Rochester tells the BBC. "But so far it seems unlikely that this star actually triggered a significant 'comet shower.'" As for that trivia question, Proxima Centauri is still the safe answer: Scholz's star, formally known as WISE J072003.20-084651.2, continued on its way and is now 20 light-years from us. (Astronomers also recently spotted a far-away "Earth twin.")